Items That Do Not Have Offers

There are two kinds of items returned by
Product Advertising API:

Regular items

Parent items

A parent item is an abstraction of a collection of items. For
example, shirt is a parent item. A shirt that is a specific size and
color would be a child of the parent item, which is called a regular
item. Each regular item has an item identifier, such as an ASIN. That
means that a red, large shirt would have a different ASIN from the same
shirt that is blue and size large. The child items are also called
variations.

Because a parent item is an abstraction, it cannot be sold so it
does not have an OfferListingId.